Recognize and handle Memory Segment View VarHandles in JDK21+

[nbhuiyan]

This PR enables UnsafeFastPath transformation to fast-path Unsafe operations that are part of Memory Segment View VarHandle usage in JDK 21 and above.

This PR depends on #19566, and will remain in draft state until it is merged.

[nbhuiyan]

@jdmpapin @0xdaryl FYI

[nbhuiyan]

@jdmpapin requesting review

[jdmpapin]

I don't think there should be extra auxiliary unsafe accesses (like the ones in byte buffer view handles) that this would mess up

However, this will attempt to transform get/put as array operations even if arraylets are in use, and that will generate a SpineCHK which IIUC will unconditionally load the contiguous length field and unexpectedly segfault when the base object is null

Soon this would also be expected to transform get/put as array operations even with off-heap arrays, which similarly will generate an unconditional load, but this time of the data address field

If we're sure that the base object for these accesses is always null - which it looked to be at a glance, but I don't really know - then we could treat them as non-array accesses, but only for int, long, float, and double. Accesses to narrow integral values in native memory would need to compute the address as though for non-array/null but then load from it in the same way as we do for array elements (i.e. narrow load + extend)

At the moment I think it will suffice to decline to transform if arraylets or off-heap are enabled. Once you rebase and pick up #19731 to resolve the conflicts (sorry), maybe it would make sense to update the isVarHandleOperationMethod() wrapper function for this